In the past decades, clothes dryers have become common in many residences. Clothes dryers require adequate DED airflow to function properly. A dryer may at times suffer performance degradation, such as extended drying times, when the DED airflow is reduced. Excessive static pressure (the pressure against which the dryer exhaust fan must blow) can be inherent from restrictions and/or turns in the duct system, or just the length of duct. The end-user is often limited in their remediation of this particular problem. Relocating the dryer or the exhaust vent can be very difficult and often impossible. One common and relatively simple solution to this problem is to install a DEDPV, which may also be called a clothes dryer booster fan system. The booster fan mounts in-line within the dryer's existing exhaust duct. The proper booster fan will provide the requisite capacity to overcome the excess static pressure in a problematic exhaust duct system.
A simplified dryer booster fan system typically requires two components: a fan, and a control means which interlocks and reports failures in the booster fan's operation.
Typically, the booster fan is only energized while the dryer's exhaust fan is operating. A common approach is to use an inside the DED pressure sensor to control the booster fan. Another method of interlocking the booster fan operation to the dryer has been to use an internal to the dryer current sensor to sense operation of the dryer. This method has the advantage over the pressure sensor method in that the booster fan starts immediately when the dryer begins, continues without interruption or cycling, and turns off when the dryer stops (or within a specified duration thereafter). When the dryer is energized, the dryer current sensor, which may be located in a junction box in the wall next to the outlet providing power to the dryer, detects current being supplied to the dryer and turns the booster fan on. When the current sensor no longer detects this dryer current (i.e.: the dryer has ended its cycle), it turns the booster fan off.
While these prior art clothes dryer vent booster fan system have enjoyed considerable success in the past, there exists a need for improvement in several respects. The following description of the present invention is intended to address some of these needs.